Pain medicine specialists at Rush have helped develop, and are among the first in the country to provide, a noninvasive treatment for knee arthritis that uses cooled radio energy to target and interrupt pain signals.

Known as “Coolief,” the procedure can provide several months of relief from chronic arthritis pain for patients for whom surgery is not an option. It also decreases the need for a daily regimen of prescription medication and other over–the–counter pain–relieving drugs.

“We’re not taking away the arthritis, just the arthritis pain,” said Dr. Amin Sandeep, a pain specialist at Rush University Medical Center and chairperson of the Department of Anesthesiology at Rush Oak Park Hospital. “We're changing the wiring of the knee to interrupt the pain signal.”

For several years, Rush pain medicine physicians have treated many types of chronic pain with radiofrequency (RF) ablation technology, which uses the heat from radio wave energy to temporarily neutralize specific nerves that cause chronic pain. The innovative Coolief RF technology combines cold and heat energy to extend the pain–free period much longer.

During the Coolief procedure, minimallyinvasive needles and water–cooled electrodes inserted into the knee target three nerves responsible for sending pain signals to the brain. RF energy passes through the needle and ablates (heats) nerve tissue, greatly reducing those nerves' ability to send pain signals to the brain for extended periods of time.

By also cooling the targeted area with the water–cooled electrodes, the Coolief procedure creates a treatment area that is larger than what occurs via conventional, heat–only RF treatments. That larger treatment area in turn extends the time the nerves need to resume sending pain signals.

This May, the U.S. Food and Drug Administration approved Coolief as the first RF treatment specifically to alleviate chronic knee pain due to osteoarthritis. That was based primarily on a 2016 clinical study showing that the Coolief system was safe and provided higher levels of pain relief for much longer time periods than intra–articular corticosteroids (cortisone injections). Dr. Asokumar Buvanendran, Rush’s director of orthopedic anesthesia, helped lead that study, and other physicians at Rush participated in it, as did several Rush patients.